Cobb County was created in 1832 from Cherokee County, originally part of the Cherokee Indian Nation. It was the 81st county in Georgia and named for Judge Thomas Willis Cobb of Virginia, who served as a U.S. Senator, state congressman and Superior Court Judge.
The county seat, Marietta, was chartered in 1834. Marietta was named for Judge Cobb's wife. The city's downtown was destroyed by General William T. Sherman's troops during the Civil War, but was reconstructed and is now home to 4 National Historic Districts listed on the National Register of Historic Places.
The county began to be transformed in 1942, when Bell Aircraft announced the opening of a Marietta branch to produce B-29 bombers. By 1945 the large government-built assembly plant provided employment for more than 28,000 workers. After World War II (1941-45), Bell Bomber closed. In 1951, during the Korean conflict, the Air Force awarded the facility to the Lockheed Corporation. Lockheed-Georgia became the nation's leading producer of transport planes, from the workhorse C-130 Hercules (first production model rollout in 1955) to the giant C-5 Galaxy (rollout 1968).
Since World War II Cobb County's population has grown steadily, from 38,272 in 1940 to 607,751 in 2000, which made it the third largest county in Georgia. By mid-2003 more than 27,000 businesses were licensed in Cobb County. The largest employer was the Cobb County Public Schools, followed by Lockheed Martin, WellStar Health System, the Home Depot, Cobb County government, and Publix.